Cavity filters serving as frequency selection devices are widely used in communication field, especially in radio frequency communications field. Filters in a base station are used for choosing communication signals and filtering out clutters or interference signals beyond the communication signal frequency. Generally the cavity filter includes a cavity, a cover, a connector and a resonance tube, the cover is located on a top surface of the cavity, the cavity includes a cavity sidewall and several separation ribs for separating the cavity to form a resonant cavity, and the connector is generally mounted on a side or a bottom of the cavity, sometimes is mounted on the top surface of the cavity.
As shown in FIGS. 1a, 1b, conventionally, the connector is mounted on the top surface of the cavity in the following manner: firstly machining a mounting slot 20 in a top surface of the isolation ribs or a top surface of the cavity sidewall, the mounting slot 20 communicates with the resonant cavity, and then installing the connector 21 in the mounting slot 20, and welding an inner conductor 210 of the connector 21 to a cable 22. The cable 22 passes through the mounting slot 20 and is extended to the resonant cavity and welded to the resonance tube 23 in the resonant cavity, in such a way, signals between the inner conductor 210 of the connector 21 and the resonant cavity are connected.
However, the conventional connector has the following disadvantages: (1) a mounting slot is required to receive the connector, which limits the space to a certain extent; (2) the structure of the connector is not compact, thus vibrations are easily generated among the components of the connector, and accumulated assembly tolerances would be generated during the assembly, the components thereof require multiple welding points for connecting, thereby communication quality is degraded and assembly efficiency is reduced; (3) the cost is high.